1. Field of the Invention
The invention relates to a press section of a machine for producing a fibrous material web, such as a paper and/or cardboard web, with at least one nip that is elongated in the direction of web travel and includes an inlet zone, a main pressing zone, and an outlet zone, where the fibrous material web is guided through the nip.
2. Discussion of Background Information
In press sections of this type, particularly where the fibrous material web to be treated has an average to high incoming dry matter content, compaction of the web surface due to excessive pressures frequently occurs. Steep pressure increases are particularly damaging in this regard. This results, among other things, in a lower pressure output in the drier section, and in a relatively low bond strength. Furthermore, this reduces the effectiveness of subsequent press processes.
When the fibrous web to be processed has a low dry matter content, it also has low strength. Moreover, with an excessive pressure increase in the direction of web travel, undesirable compression of the web in the nip may result. A danger of this kind of compression exists particularly for fibrous web material having a surface weight measured in g/m.sup.2 in the high range.